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Re: Function Talks at Ostrom Symposium

Thomas R. Holtz, Jr said:
> Others asked why would it be that a hypothetical
>  diaphragm breathing would be incapable of being the ancestor of birds.
 So did they let Ruben answer? It seems he answered that question in the
11/14/97 Science, p. 1269, where he says that a "diaphragm ventilating
ancestor would have necessated selection for a diaphragmatic hernia in taxa
transitional between theropods and birds. Such a debilitating condition would
have immediately compromised the entire pulmonary ventilatory apparatus and
seems unlikely to have been of any selective advantage."
So is it answered in advance?